Refactor COPY FROM to use format callback functions.

This commit introduces a new CopyFromRoutine struct, which is a set of
callback routines to read tuples in a specific format. It also makes
COPY FROM with the existing formats (text, CSV, and binary) utilize
these format callbacks.

This change is a preliminary step towards making the COPY FROM command
extensible in terms of input formats.

Similar to 2e4127b6d2d, this refactoring contributes to a performance
improvement by reducing the number of "if" branches that need to be
checked on a per-row basis when sending field representations in text
or CSV mode. The performance benchmark results showed ~5% performance
gain in text or CSV mode.

Author: Sutou Kouhei <kou@clear-code.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com>
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://postgr.es/m/20231204.153548.2126325458835528809.kou@clear-code.com

1 files changed, 248 insertions, 198 deletions

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index caccdc8563c..bad577aa67b 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -62,7 +62,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 
-#include "commands/copy.h"
+#include "commands/copyapi.h"
 #include "commands/copyfrom_internal.h"
 #include "commands/progress.h"
 #include "executor/executor.h"
@@ -140,13 +140,18 @@ static const char BinarySignature[11] = "PGCOPY\n\377\r\n\0";
 
 
 /* non-export function prototypes */
-static bool CopyReadLine(CopyFromState cstate);
-static bool CopyReadLineText(CopyFromState cstate);
+static bool CopyReadLine(CopyFromState cstate, bool is_csv);
+static bool CopyReadLineText(CopyFromState cstate, bool is_csv);
 static int	CopyReadAttributesText(CopyFromState cstate);
 static int	CopyReadAttributesCSV(CopyFromState cstate);
 static Datum CopyReadBinaryAttribute(CopyFromState cstate, FmgrInfo *flinfo,
 									 Oid typioparam, int32 typmod,
 									 bool *isnull);
+static pg_attribute_always_inline bool CopyFromTextLikeOneRow(CopyFromState cstate,
+															  ExprContext *econtext,
+															  Datum *values,
+															  bool *nulls,
+															  bool is_csv);
 
 
 /* Low-level communications functions */
@@ -740,9 +745,12 @@ CopyReadBinaryData(CopyFromState cstate, char *dest, int nbytes)
  * in the relation.
  *
  * NOTE: force_not_null option are not applied to the returned fields.
+ *
+ * We use pg_attribute_always_inline to reduce function call overhead
+ * and to help compilers to optimize away the 'is_csv' condition.
  */
-bool
-NextCopyFromRawFields(CopyFromState cstate, char ***fields, int *nfields)
+static pg_attribute_always_inline bool
+NextCopyFromRawFields(CopyFromState cstate, char ***fields, int *nfields, bool is_csv)
 {
 	int			fldct;
 	bool		done;
@@ -759,13 +767,13 @@ NextCopyFromRawFields(CopyFromState cstate, char ***fields, int *nfields)
 		tupDesc = RelationGetDescr(cstate->rel);
 
 		cstate->cur_lineno++;
-		done = CopyReadLine(cstate);
+		done = CopyReadLine(cstate, is_csv);
 
 		if (cstate->opts.header_line == COPY_HEADER_MATCH)
 		{
 			int			fldnum;
 
-			if (cstate->opts.csv_mode)
+			if (is_csv)
 				fldct = CopyReadAttributesCSV(cstate);
 			else
 				fldct = CopyReadAttributesText(cstate);
@@ -809,7 +817,7 @@ NextCopyFromRawFields(CopyFromState cstate, char ***fields, int *nfields)
 	cstate->cur_lineno++;
 
 	/* Actually read the line into memory here */
-	done = CopyReadLine(cstate);
+	done = CopyReadLine(cstate, is_csv);
 
 	/*
 	 * EOF at start of line means we're done.  If we see EOF after some
@@ -820,7 +828,7 @@ NextCopyFromRawFields(CopyFromState cstate, char ***fields, int *nfields)
 		return false;
 
 	/* Parse the line into de-escaped field values */
-	if (cstate->opts.csv_mode)
+	if (is_csv)
 		fldct = CopyReadAttributesCSV(cstate);
 	else
 		fldct = CopyReadAttributesText(cstate);
@@ -847,233 +855,275 @@ NextCopyFrom(CopyFromState cstate, ExprContext *econtext,
 {
 	TupleDesc	tupDesc;
 	AttrNumber	num_phys_attrs,
-				attr_count,
 				num_defaults = cstate->num_defaults;
-	FmgrInfo   *in_functions = cstate->in_functions;
-	Oid		   *typioparams = cstate->typioparams;
 	int			i;
 	int		   *defmap = cstate->defmap;
 	ExprState **defexprs = cstate->defexprs;
 
 	tupDesc = RelationGetDescr(cstate->rel);
 	num_phys_attrs = tupDesc->natts;
-	attr_count = list_length(cstate->attnumlist);
 
 	/* Initialize all values for row to NULL */
 	MemSet(values, 0, num_phys_attrs * sizeof(Datum));
 	MemSet(nulls, true, num_phys_attrs * sizeof(bool));
 	MemSet(cstate->defaults, false, num_phys_attrs * sizeof(bool));
 
-	if (!cstate->opts.binary)
+	/* Get one row from source */
+	if (!cstate->routine->CopyFromOneRow(cstate, econtext, values, nulls))
+		return false;
+
+	/*
+	 * Now compute and insert any defaults available for the columns not
+	 * provided by the input data.  Anything not processed here or above will
+	 * remain NULL.
+	 */
+	for (i = 0; i < num_defaults; i++)
 	{
-		char	  **field_strings;
-		ListCell   *cur;
-		int			fldct;
-		int			fieldno;
-		char	   *string;
+		/*
+		 * The caller must supply econtext and have switched into the
+		 * per-tuple memory context in it.
+		 */
+		Assert(econtext != NULL);
+		Assert(CurrentMemoryContext == econtext->ecxt_per_tuple_memory);
 
-		/* read raw fields in the next line */
-		if (!NextCopyFromRawFields(cstate, &field_strings, &fldct))
-			return false;
+		values[defmap[i]] = ExecEvalExpr(defexprs[defmap[i]], econtext,
+										 &nulls[defmap[i]]);
+	}
+
+	return true;
+}
+
+/* Implementation of the per-row callback for text format */
+bool
+CopyFromTextOneRow(CopyFromState cstate, ExprContext *econtext, Datum *values,
+				   bool *nulls)
+{
+	return CopyFromTextLikeOneRow(cstate, econtext, values, nulls, false);
+}
+
+/* Implementation of the per-row callback for CSV format */
+bool
+CopyFromCSVOneRow(CopyFromState cstate, ExprContext *econtext, Datum *values,
+				  bool *nulls)
+{
+	return CopyFromTextLikeOneRow(cstate, econtext, values, nulls, true);
+}
 
-		/* check for overflowing fields */
-		if (attr_count > 0 && fldct > attr_count)
+/*
+ * Workhorse for CopyFromTextOneRow() and CopyFromCSVOneRow().
+ *
+ * We use pg_attribute_always_inline to reduce function call overhead
+ * and to help compilers to optimize away the 'is_csv' condition.
+ */
+static pg_attribute_always_inline bool
+CopyFromTextLikeOneRow(CopyFromState cstate, ExprContext *econtext,
+					   Datum *values, bool *nulls, bool is_csv)
+{
+	TupleDesc	tupDesc;
+	AttrNumber	attr_count;
+	FmgrInfo   *in_functions = cstate->in_functions;
+	Oid		   *typioparams = cstate->typioparams;
+	ExprState **defexprs = cstate->defexprs;
+	char	  **field_strings;
+	ListCell   *cur;
+	int			fldct;
+	int			fieldno;
+	char	   *string;
+
+	tupDesc = RelationGetDescr(cstate->rel);
+	attr_count = list_length(cstate->attnumlist);
+
+	/* read raw fields in the next line */
+	if (!NextCopyFromRawFields(cstate, &field_strings, &fldct, is_csv))
+		return false;
+
+	/* check for overflowing fields */
+	if (attr_count > 0 && fldct > attr_count)
+		ereport(ERROR,
+				(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
+				 errmsg("extra data after last expected column")));
+
+	fieldno = 0;
+
+	/* Loop to read the user attributes on the line. */
+	foreach(cur, cstate->attnumlist)
+	{
+		int			attnum = lfirst_int(cur);
+		int			m = attnum - 1;
+		Form_pg_attribute att = TupleDescAttr(tupDesc, m);
+
+		if (fieldno >= fldct)
 			ereport(ERROR,
 					(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
-					 errmsg("extra data after last expected column")));
-
-		fieldno = 0;
+					 errmsg("missing data for column \"%s\"",
+							NameStr(att->attname))));
+		string = field_strings[fieldno++];
 
-		/* Loop to read the user attributes on the line. */
-		foreach(cur, cstate->attnumlist)
+		if (cstate->convert_select_flags &&
+			!cstate->convert_select_flags[m])
 		{
-			int			attnum = lfirst_int(cur);
-			int			m = attnum - 1;
-			Form_pg_attribute att = TupleDescAttr(tupDesc, m);
-
-			if (fieldno >= fldct)
-				ereport(ERROR,
-						(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
-						 errmsg("missing data for column \"%s\"",
-								NameStr(att->attname))));
-			string = field_strings[fieldno++];
+			/* ignore input field, leaving column as NULL */
+			continue;
+		}
 
-			if (cstate->convert_select_flags &&
-				!cstate->convert_select_flags[m])
+		if (is_csv)
+		{
+			if (string == NULL &&
+				cstate->opts.force_notnull_flags[m])
 			{
-				/* ignore input field, leaving column as NULL */
-				continue;
+				/*
+				 * FORCE_NOT_NULL option is set and column is NULL - convert
+				 * it to the NULL string.
+				 */
+				string = cstate->opts.null_print;
 			}
-
-			if (cstate->opts.csv_mode)
+			else if (string != NULL && cstate->opts.force_null_flags[m]
+					 && strcmp(string, cstate->opts.null_print) == 0)
 			{
-				if (string == NULL &&
-					cstate->opts.force_notnull_flags[m])
-				{
-					/*
-					 * FORCE_NOT_NULL option is set and column is NULL -
-					 * convert it to the NULL string.
-					 */
-					string = cstate->opts.null_print;
-				}
-				else if (string != NULL && cstate->opts.force_null_flags[m]
-						 && strcmp(string, cstate->opts.null_print) == 0)
-				{
-					/*
-					 * FORCE_NULL option is set and column matches the NULL
-					 * string. It must have been quoted, or otherwise the
-					 * string would already have been set to NULL. Convert it
-					 * to NULL as specified.
-					 */
-					string = NULL;
-				}
+				/*
+				 * FORCE_NULL option is set and column matches the NULL
+				 * string. It must have been quoted, or otherwise the string
+				 * would already have been set to NULL. Convert it to NULL as
+				 * specified.
+				 */
+				string = NULL;
 			}
+		}
 
-			cstate->cur_attname = NameStr(att->attname);
-			cstate->cur_attval = string;
+		cstate->cur_attname = NameStr(att->attname);
+		cstate->cur_attval = string;
 
-			if (string != NULL)
-				nulls[m] = false;
+		if (string != NULL)
+			nulls[m] = false;
 
-			if (cstate->defaults[m])
-			{
-				/*
-				 * The caller must supply econtext and have switched into the
-				 * per-tuple memory context in it.
-				 */
-				Assert(econtext != NULL);
-				Assert(CurrentMemoryContext == econtext->ecxt_per_tuple_memory);
+		if (cstate->defaults[m])
+		{
+			/* We must have switched into the per-tuple memory context */
+			Assert(econtext != NULL);
+			Assert(CurrentMemoryContext == econtext->ecxt_per_tuple_memory);
 
-				values[m] = ExecEvalExpr(defexprs[m], econtext, &nulls[m]);
-			}
+			values[m] = ExecEvalExpr(defexprs[m], econtext, &nulls[m]);
+		}
 
-			/*
-			 * If ON_ERROR is specified with IGNORE, skip rows with soft
-			 * errors
-			 */
-			else if (!InputFunctionCallSafe(&in_functions[m],
-											string,
-											typioparams[m],
-											att->atttypmod,
-											(Node *) cstate->escontext,
-											&values[m]))
-			{
-				Assert(cstate->opts.on_error != COPY_ON_ERROR_STOP);
+		/*
+		 * If ON_ERROR is specified with IGNORE, skip rows with soft errors
+		 */
+		else if (!InputFunctionCallSafe(&in_functions[m],
+										string,
+										typioparams[m],
+										att->atttypmod,
+										(Node *) cstate->escontext,
+										&values[m]))
+		{
+			Assert(cstate->opts.on_error != COPY_ON_ERROR_STOP);
 
-				cstate->num_errors++;
+			cstate->num_errors++;
 
-				if (cstate->opts.log_verbosity == COPY_LOG_VERBOSITY_VERBOSE)
-				{
-					/*
-					 * Since we emit line number and column info in the below
-					 * notice message, we suppress error context information
-					 * other than the relation name.
-					 */
-					Assert(!cstate->relname_only);
-					cstate->relname_only = true;
+			if (cstate->opts.log_verbosity == COPY_LOG_VERBOSITY_VERBOSE)
+			{
+				/*
+				 * Since we emit line number and column info in the below
+				 * notice message, we suppress error context information other
+				 * than the relation name.
+				 */
+				Assert(!cstate->relname_only);
+				cstate->relname_only = true;
 
-					if (cstate->cur_attval)
-					{
-						char	   *attval;
-
-						attval = CopyLimitPrintoutLength(cstate->cur_attval);
-						ereport(NOTICE,
-								errmsg("skipping row due to data type incompatibility at line %llu for column \"%s\": \"%s\"",
-									   (unsigned long long) cstate->cur_lineno,
-									   cstate->cur_attname,
-									   attval));
-						pfree(attval);
-					}
-					else
-						ereport(NOTICE,
-								errmsg("skipping row due to data type incompatibility at line %llu for column \"%s\": null input",
-									   (unsigned long long) cstate->cur_lineno,
-									   cstate->cur_attname));
-
-					/* reset relname_only */
-					cstate->relname_only = false;
+				if (cstate->cur_attval)
+				{
+					char	   *attval;
+
+					attval = CopyLimitPrintoutLength(cstate->cur_attval);
+					ereport(NOTICE,
+							errmsg("skipping row due to data type incompatibility at line %llu for column \"%s\": \"%s\"",
+								   (unsigned long long) cstate->cur_lineno,
+								   cstate->cur_attname,
+								   attval));
+					pfree(attval);
 				}
+				else
+					ereport(NOTICE,
+							errmsg("skipping row due to data type incompatibility at line %llu for column \"%s\": null input",
+								   (unsigned long long) cstate->cur_lineno,
+								   cstate->cur_attname));
 
-				return true;
+				/* reset relname_only */
+				cstate->relname_only = false;
 			}
 
-			cstate->cur_attname = NULL;
-			cstate->cur_attval = NULL;
+			return true;
 		}
 
-		Assert(fieldno == attr_count);
+		cstate->cur_attname = NULL;
+		cstate->cur_attval = NULL;
 	}
-	else
-	{
-		/* binary */
-		int16		fld_count;
-		ListCell   *cur;
 
-		cstate->cur_lineno++;
+	Assert(fieldno == attr_count);
 
-		if (!CopyGetInt16(cstate, &fld_count))
-		{
-			/* EOF detected (end of file, or protocol-level EOF) */
-			return false;
-		}
+	return true;
+}
 
-		if (fld_count == -1)
-		{
-			/*
-			 * Received EOF marker.  Wait for the protocol-level EOF, and
-			 * complain if it doesn't come immediately.  In COPY FROM STDIN,
-			 * this ensures that we correctly handle CopyFail, if client
-			 * chooses to send that now.  When copying from file, we could
-			 * ignore the rest of the file like in text mode, but we choose to
-			 * be consistent with the COPY FROM STDIN case.
-			 */
-			char		dummy;
+/* Implementation of the per-row callback for binary format */
+bool
+CopyFromBinaryOneRow(CopyFromState cstate, ExprContext *econtext, Datum *values,
+					 bool *nulls)
+{
+	TupleDesc	tupDesc;
+	AttrNumber	attr_count;
+	FmgrInfo   *in_functions = cstate->in_functions;
+	Oid		   *typioparams = cstate->typioparams;
+	int16		fld_count;
+	ListCell   *cur;
 
-			if (CopyReadBinaryData(cstate, &dummy, 1) > 0)
-				ereport(ERROR,
-						(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
-						 errmsg("received copy data after EOF marker")));
-			return false;
-		}
+	tupDesc = RelationGetDescr(cstate->rel);
+	attr_count = list_length(cstate->attnumlist);
 
-		if (fld_count != attr_count)
-			ereport(ERROR,
-					(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
-					 errmsg("row field count is %d, expected %d",
-							(int) fld_count, attr_count)));
+	cstate->cur_lineno++;
 
-		foreach(cur, cstate->attnumlist)
-		{
-			int			attnum = lfirst_int(cur);
-			int			m = attnum - 1;
-			Form_pg_attribute att = TupleDescAttr(tupDesc, m);
-
-			cstate->cur_attname = NameStr(att->attname);
-			values[m] = CopyReadBinaryAttribute(cstate,
-												&in_functions[m],
-												typioparams[m],
-												att->atttypmod,
-												&nulls[m]);
-			cstate->cur_attname = NULL;
-		}
+	if (!CopyGetInt16(cstate, &fld_count))
+	{
+		/* EOF detected (end of file, or protocol-level EOF) */
+		return false;
 	}
 
-	/*
-	 * Now compute and insert any defaults available for the columns not
-	 * provided by the input data.  Anything not processed here or above will
-	 * remain NULL.
-	 */
-	for (i = 0; i < num_defaults; i++)
+	if (fld_count == -1)
 	{
 		/*
-		 * The caller must supply econtext and have switched into the
-		 * per-tuple memory context in it.
+		 * Received EOF marker.  Wait for the protocol-level EOF, and complain
+		 * if it doesn't come immediately.  In COPY FROM STDIN, this ensures
+		 * that we correctly handle CopyFail, if client chooses to send that
+		 * now.  When copying from file, we could ignore the rest of the file
+		 * like in text mode, but we choose to be consistent with the COPY
+		 * FROM STDIN case.
 		 */
-		Assert(econtext != NULL);
-		Assert(CurrentMemoryContext == econtext->ecxt_per_tuple_memory);
+		char		dummy;
 
-		values[defmap[i]] = ExecEvalExpr(defexprs[defmap[i]], econtext,
-										 &nulls[defmap[i]]);
+		if (CopyReadBinaryData(cstate, &dummy, 1) > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
+					 errmsg("received copy data after EOF marker")));
+		return false;
+	}
+
+	if (fld_count != attr_count)
+		ereport(ERROR,
+				(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
+				 errmsg("row field count is %d, expected %d",
+						(int) fld_count, attr_count)));
+
+	foreach(cur, cstate->attnumlist)
+	{
+		int			attnum = lfirst_int(cur);
+		int			m = attnum - 1;
+		Form_pg_attribute att = TupleDescAttr(tupDesc, m);
+
+		cstate->cur_attname = NameStr(att->attname);
+		values[m] = CopyReadBinaryAttribute(cstate,
+											&in_functions[m],
+											typioparams[m],
+											att->atttypmod,
+											&nulls[m]);
+		cstate->cur_attname = NULL;
 	}
 
 	return true;
@@ -1087,7 +1137,7 @@ NextCopyFrom(CopyFromState cstate, ExprContext *econtext,
  * in the final value of line_buf.
  */
 static bool
-CopyReadLine(CopyFromState cstate)
+CopyReadLine(CopyFromState cstate, bool is_csv)
 {
 	bool		result;
 
@@ -1095,7 +1145,7 @@ CopyReadLine(CopyFromState cstate)
 	cstate->line_buf_valid = false;
 
 	/* Parse data and transfer into line_buf */
-	result = CopyReadLineText(cstate);
+	result = CopyReadLineText(cstate, is_csv);
 
 	if (result)
 	{
@@ -1163,7 +1213,7 @@ CopyReadLine(CopyFromState cstate)
  * CopyReadLineText - inner loop of CopyReadLine for text mode
  */
 static bool
-CopyReadLineText(CopyFromState cstate)
+CopyReadLineText(CopyFromState cstate, bool is_csv)
 {
 	char	   *copy_input_buf;
 	int			input_buf_ptr;
@@ -1178,7 +1228,7 @@ CopyReadLineText(CopyFromState cstate)
 	char		quotec = '\0';
 	char		escapec = '\0';
 
-	if (cstate->opts.csv_mode)
+	if (is_csv)
 	{
 		quotec = cstate->opts.quote[0];
 		escapec = cstate->opts.escape[0];
@@ -1255,7 +1305,7 @@ CopyReadLineText(CopyFromState cstate)
 		prev_raw_ptr = input_buf_ptr;
 		c = copy_input_buf[input_buf_ptr++];
 
-		if (cstate->opts.csv_mode)
+		if (is_csv)
 		{
 			/*
 			 * If character is '\r', we may need to look ahead below.  Force
@@ -1294,7 +1344,7 @@ CopyReadLineText(CopyFromState cstate)
 		}
 
 		/* Process \r */
-		if (c == '\r' && (!cstate->opts.csv_mode || !in_quote))
+		if (c == '\r' && (!is_csv || !in_quote))
 		{
 			/* Check for \r\n on first line, _and_ handle \r\n. */
 			if (cstate->eol_type == EOL_UNKNOWN ||
@@ -1322,10 +1372,10 @@ CopyReadLineText(CopyFromState cstate)
 					if (cstate->eol_type == EOL_CRNL)
 						ereport(ERROR,
 								(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
-								 !cstate->opts.csv_mode ?
+								 !is_csv ?
 								 errmsg("literal carriage return found in data") :
 								 errmsg("unquoted carriage return found in data"),
-								 !cstate->opts.csv_mode ?
+								 !is_csv ?
 								 errhint("Use \"\\r\" to represent carriage return.") :
 								 errhint("Use quoted CSV field to represent carriage return.")));
 
@@ -1339,10 +1389,10 @@ CopyReadLineText(CopyFromState cstate)
 			else if (cstate->eol_type == EOL_NL)
 				ereport(ERROR,
 						(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
-						 !cstate->opts.csv_mode ?
+						 !is_csv ?
 						 errmsg("literal carriage return found in data") :
 						 errmsg("unquoted carriage return found in data"),
-						 !cstate->opts.csv_mode ?
+						 !is_csv ?
 						 errhint("Use \"\\r\" to represent carriage return.") :
 						 errhint("Use quoted CSV field to represent carriage return.")));
 			/* If reach here, we have found the line terminator */
@@ -1350,15 +1400,15 @@ CopyReadLineText(CopyFromState cstate)
 		}
 
 		/* Process \n */
-		if (c == '\n' && (!cstate->opts.csv_mode || !in_quote))
+		if (c == '\n' && (!is_csv || !in_quote))
 		{
 			if (cstate->eol_type == EOL_CR || cstate->eol_type == EOL_CRNL)
 				ereport(ERROR,
 						(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
-						 !cstate->opts.csv_mode ?
+						 !is_csv ?
 						 errmsg("literal newline found in data") :
 						 errmsg("unquoted newline found in data"),
-						 !cstate->opts.csv_mode ?
+						 !is_csv ?
 						 errhint("Use \"\\n\" to represent newline.") :
 						 errhint("Use quoted CSV field to represent newline.")));
 			cstate->eol_type = EOL_NL;	/* in case not set yet */
@@ -1370,7 +1420,7 @@ CopyReadLineText(CopyFromState cstate)
 		 * Process backslash, except in CSV mode where backslash is a normal
 		 * character.
 		 */
-		if (c == '\\' && !cstate->opts.csv_mode)
+		if (c == '\\' && !is_csv)
 		{
 			char		c2;